Collectors · Research & science

Clinical trials API in Python

Studies from ClinicalTrials.gov — status, phase, conditions, interventions, sponsor. One POST from Python with the input, rows back as JSON with 34 fields, $0.0005 per delivered study. No proxies or parsers to maintain.

Get an API key See the collector

A Python requests snippet that posts { — A Python requests call to the clinical_trials collector returns one dict per study, at $0.0005 each.

First call

Install, call, read the rows.

pip install requests

The only dependency.

import os, requests

r = requests.post(
    "https://api.quanticdata.io/v1/scraper/collectors/clinical_trials/run",
    headers={"Authorization": f"Bearer {os.environ['QD_API_KEY']}"},
    json={
        "query": "cancer immunotherapy",
        "status": "RECRUITING",
        "max_results": 20,
    },
    timeout=120,
)
r.raise_for_status()
run = r.json()["payload"]
print(run["count"], "rows,", run["cost"]["usd"], "USD")
for row in run["results"]:
    print(row.get("nct_id"), row.get("title"), row.get("status"), row.get("phases"))

Python: one Clinical trials (ClinicalTrials.gov) run (Per termine), printing nct_id, title, status, phases

The key comes from an environment variable, never from the code. The run answers in the same request when it finishes in time; payload.results holds the rows and payload.cost what they cost.

Request parameters

What the collector takes.

Input of the Clinical trials (ClinicalTrials.gov) collector
Parameter	Type	Required	Meaning
`query`	string	no	Free-text search term (drug, disease, sponsor…).
`condition`	string	no	Restrict to a medical condition.
`status`	string: `RECRUITING`, `NOT_YET_RECRUITING`, `ACTIVE_NOT_RECRUITING`, `COMPLETED`, `ENROLLING_BY_INVITATION`, `SUSPENDED`, `TERMINATED`, `WITHDRAWN`	no	Recruitment status filter.
`max_results`	integer	no (default 20)	How many studies to deliver at most (1–200). You pay only for delivered studies.

Response fields

34 fields per study.

Fields of each row (study)
Field	Type	What it holds
`rank`	integer	1-based position.
`nct_id`	string	ClinicalTrials.gov NCT id.
`title`	string, nullable	Brief title.
`status`	string, nullable	Overall recruitment status.
`phases`	string[]	Trial phase(s).
`study_type`	string, nullable	Interventional, Observational…
`conditions`	string[]	Conditions studied.
`interventions`	string[]	Interventions/treatments.
`sponsor`	string, nullable	Lead sponsor.
`enrollment`	integer, nullable	Planned/actual enrollment.
`start_date`	string, nullable	Study start date.
`completion_date`	string, nullable	Study completion date.
`has_results`	boolean	Whether results are posted.
`url`	string	Study page URL.
`official_title`	string, nullable	Official title.
`acronym`	string, nullable	Study acronym.
`allocation`	string, nullable	Allocation (RANDOMIZED…).
`masking`	string, nullable	Masking (NONE, DOUBLE…).
`primary_purpose`	string, nullable	Primary purpose (TREATMENT, PREVENTION…).
`intervention_types`	string[]	Intervention types (DRUG, DEVICE, BIOLOGICAL…).
`sponsor_class`	string, nullable	Lead sponsor class (INDUSTRY, NIH, OTHER…).
`collaborators`	string[]	Collaborating organisations.
`enrollment_type`	string, nullable	ACTUAL or ESTIMATED.
`primary_completion_date`	string, nullable	Primary completion date.
`first_posted`	string, nullable	Date first posted.
`last_updated`	string, nullable	Date last updated.
`sex`	string, nullable	Eligible sex (ALL, FEMALE, MALE).
`minimum_age`	string, nullable	Minimum age.
`maximum_age`	string, nullable	Maximum age.
`healthy_volunteers`	boolean, nullable	Whether healthy volunteers are accepted.
`primary_outcomes`	string[]	Primary outcome measures (up to 5).
`locations_count`	integer	Number of study sites.
`countries`	string[]	Countries with a study site.
`summary`	string, nullable	Brief summary (up to 1,500 characters).

Add ?format=csv to the runs endpoint to get the same rows as CSV.

Long runs

Run in the background, then poll.

A run that needs more time can go to the background: send "async": true, get 202 with the run id, and poll the runs endpoint until the status is done. Reading a run is free.

import os, time, requests

H = {"Authorization": f"Bearer {os.environ['QD_API_KEY']}"}
r = requests.post("https://api.quanticdata.io/v1/scraper/collectors/clinical_trials/run", headers=H,
                  json={**{"query":"cancer immunotherapy","status":"RECRUITING","max_results":20}, "async": True}, timeout=30)
run_id = r.json()["payload"]["run_id"]
while True:
    run = requests.get(f"https://api.quanticdata.io/v1/scraper/collectors/runs/{run_id}", headers=H, timeout=30).json()["payload"]
    if run["status"] in ("done", "failed"):
        break
    time.sleep(5)
print(run["status"], run["count"])

Python: background run and polling

Errors

What can come back, and what is billed.

Collector run errors
Status	Meaning	Billed
`400`	The input does not match the collector (`payload.errors`)	No
`401`	Missing or wrong API key	No
`402`	Balance and free credit do not cover the run: top up	No
`422`	The input can never resolve; retrying the same input cannot help	No
`424`	The run failed at the source (blocked, timed out, layout changed); safe to retry	No
`429`	Rate limit or a per-account brake; wait for `Retry-After`	No

Only delivered rows are billed: a run that delivers nothing costs nothing.

Price

$0.0005 per delivered study.

What Clinical trials (ClinicalTrials.gov) rows cost at list price
Rows	Cost
1	$0.0005
1,000	$0.50
10,000	$5.00

Up to 200 studies per run; split larger jobs into several runs. The $2 free credit every month covers about 4,000 studies. No subscription; paid tiers lower the unit price. All collector prices: collector pricing.

Before you run it

Questions developers ask

Is there a free Clinical trials (ClinicalTrials.gov) API?

Every account gets $2 of free usage each month, about 4,000 studies of this collector at $0.0005 each, with no card.

Do I have to handle proxies, retries or blocks?

No. The collector runs on our network and handles them; a run blocked at the source returns 424 and is not billed.

How many rows can one run return?

Up to 200 studies per run (the max_results input, where the collector has one).

Can an AI agent run it?

Yes: the MCP server exposes it as the run_collector tool, with the same input and price. See the MCP server.

Run it on the free credit.

Create an API key, export it as QD_API_KEY and run the example. $0.0005 per delivered study, no subscription.

Get an API key Clinical trials API